Golf tee with support prongs

ABSTRACT

A golf tee includes: an elongate shaft having opposed upper and lower ends, the lower end configured to be inserted into an underlying surface; and a support cup that is configured to support a golf ball from beneath and that merges with the shaft. The support cup has a base portion and further includes at least three arcuate support prongs projecting upwardly from the base portion. The support prongs define a discontinuous annulus about the periphery of the support cup.

RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 15/379,627, filed Dec. 15, 2016, which is acontinuation of and claims priority to U.S. patent application Ser. No.15/054,495, filed Feb. 26, 2016 (abandoned), which is a continuation ofand claims priority to U.S. patent application Ser. No. 14/570,699,filed Dec. 15, 2014 (abandoned), which is a continuation of and claimspriority to U.S. patent application Ser. No. 14/062,417, filed Oct. 24,2013 (abandoned), which is a continuation of and claims priority to U.S.patent application Ser. No. 13/771,814, filed Feb. 20, 2013 (abandoned),which is a continuation of and claims priority to U.S. patentapplication Ser. No. 13/297,707, filed on Nov. 16, 2011 (abandoned),which is a continuation of and claims priority to U.S. patentapplication Ser. No. 12/499,251, filed Jul. 8, 2009 (abandoned) which isa continuation of and claims priority to U.S. patent application Ser.No. 11/760,956, filed Jun. 11, 2007 (abandoned) which is a continuationof and claims priority to U.S. patent application Ser. No. 10/750,710,filed Jan. 2, 2004 (abandoned), the disclosures of which are herebyincorporated herein in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to golf equipment, and morespecifically to golf tees employed in striking a golf ball.

BACKGROUND OF THE INVENTION

The overwhelming majority of golfers use golf tees during their roundsof golf. As is well-known, a golf tee is placed in the ground or otherunderlying surface, and the ball rests atop the tee; because the ballresides above the ground, there is more margin for error in striking theball with a golf club, and often greater distance can be achieved when atee is used. A golfer is permitted to use a tee on the first shot ofevery hole.

A conventional golf tee is formed of wood and typically includes acupped support surface upon which a golf ball rests and a cylindricalshaft underlying the support surface that penetrates the ground. Thesupport surface has a radius of curvature that is approximately equal tothat of a golf ball. The rim of the support surface, which typically hasa diameter of about 0.500 inch, ordinarily has a relatively sharp edge.The shaft of a conventional tee is substantially cylindrical andterminates in a pointed tip to facilitate insertion into the ground.

One of the problems with a conventional tee results from the interactionbetween the support surface and the ball as the ball is struck. Morespecifically, most, if not all, of the support surface of the tee is incontact with the ball as the ball rests thereon. This contact createsfriction that can negatively impact the launch of the ball from the tee.In addition, the sharp edges and any imperfections of the rim of the teecan “catch” on the surface of the ball and further increase the frictionon the launched ball as well as impart a degree of side spin onto theball that can reduce accuracy. Also, the sharp rim of the tee is alsosomewhat fragile and can be damaged as the club face strikes it.

In addition, a conventional tee typically has a cylindrical shank thatis uniform in diameter from just below the cupped support surface towithin about 0.150″ of the tee bottom, at which point the tee taperssharply to the tip. The uniform diameter of a conventional tee tends tocreate a cylindrical hole in the ground. When the ball/tee is struckwith a golf club, a significant portion of the force (often about 30-40lbs) is concentrated into the tee to ground interface. A common failuremechanism of wooden tees is fracture at that interface point because thetee cannot smoothly exit the ground from the cylindrical hole.

SUMMARY OF THE INVENTION

These and other issues may be addressed by a golf tee of the presentinvention. As a first aspect, the present invention is directed toembodiments of a golf tee comprising: an elongate shaft having opposedupper and lower ends, the lower end configured to be inserted into anunderlying surface; and a support cup that is configured to support agolf ball from beneath and that merges with the shaft. The support cuphas a base portion and further includes at least three arcuate supportprongs projecting upwardly from the base portion. The support prongsdefine a discontinuous annulus about the periphery of the support cup.In this configuration, the contact area between the support cup and theball can be reduced, which can in turn reduce the amount of frictionbetween the ball and tee and decrease the risk of imperfections in thetee negatively impacting ball flight.

In some embodiments, the upper surface of the base portion of thesupport cup is recessed from the support prongs. In certain embodiments,the shaft includes flutes or other projections or recesses that canresist twisting of the tee during impact.

As a second aspect, the present invention is directed to embodiments ofa golf tee comprising: an elongate shaft having opposed upper and lowerends, the lower end configured to be inserted into an underlyingsurface; and a support cup that is configured to support a golf ballfrom beneath and that merges with the shaft. As with the embodimentsdescribed above, the support cup has a base portion and further includesat least three arcuate support prongs projecting upwardly from the baseportion. In these embodiments, each of the support prongs has a convexcontact surface and is of a secant length that is greater than that of adimple of a golf ball. Again, in this configuration, the contact areabetween the support cup and the ball can be reduced to that portion ofthe golf ball that is outside the golf ball dimples.

As a third aspect, the present invention is directed to embodiments of agolf tee comprising a shaft and a support cup as described immediatelyabove, wherein each of the support prongs has a convex contact surfaceand a secant length such that the total contact area between the contactsurfaces and a golf ball resting on the contact surfaces is betweenabout 0.0036 and 0.0045 in².

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a bottom perspective view of an embodiment of a golf tee inaccordance with the present invention.

FIG. 2 is a top view of the golf tee of FIG. 1.

FIG. 2A is a top view of the golf tee of FIG. 1 with a golf ballillustrated in phantom line.

FIG. 3 is an enlarged partial top perspective view of the golf tee ofFIG. 1 showing an exemplary golf ball dimple in comparison to thesupport prong.

FIG. 4 is a side view of the golf tee of FIG. 1 inserted into the groundwith a golf ball resting on the support prongs of the tee.

FIG. 5 is a section view of the golf tee of FIG. 1 inserted into theground with a golf ball resting on the support prongs of the tee.

FIG. 5A is an enlarged section view of FIG. 4 showing support prongssupporting a golf ball.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention will be described more particularly hereinafterwith reference to the accompanying drawings. The invention is notintended to be limited to the illustrated embodiments; rather, theseembodiments are intended to fully and completely disclose the inventionto those skilled in this art. Like numbers refer to like componentsthroughout, and certain dimensions and thicknesses may be exaggeratedfor clarity.

Referring now to FIG. 1, a golf tee, designated broadly at 10, isillustrated therein. The tee 10 includes an elongate shaft 12 and asupport cup 20 attached to and merging with the upper end thereof. Thesestructures are described in greater detail below.

Referring now to FIGS. 1 and 3, the shaft 12 comprises a main body 14and a tip 18 at its lower end. The body 14 has a length of between about2.7 and 3.0 inches. In the illustrated embodiment, the body 14 istapered (i.e., it decreases in diameter with increasing distance fromthe support cup 20), with the maximum dimension being between about 0.2and 0.3 inch and the minimum dimension being between about 0.16 and 0.19inch. When viewed from the side as in FIG. 5, the taper of the body 14is such that the body defines a taper angle α of between about 0.75 and1.5 degrees. The body 14 may optionally include one or more recessedflutes 16 a, 16 b that are positioned diametrically opposed from oneanother and that extend over a major portion of the length of the body14. The flutes 16 a, 16 b (or other recesses into or projections fromthe main body 14) may prevent twisting of the tee 10 during impact. Thetip 18 tapers quickly from the end of the body 14 to terminate in asharp point; the tip typically has a length of between about 0.15 and0.25 inch.

Referring now to FIGS. 1, 2 and 3, the support cup 20 includes a baseportion 22 and four support prongs 26 a, 26 b, 26 c, 26 d. The baseportion 22 is connected to and merges with the upper end of the shaftbody 14. The base portion 22 has a concave upper surface 24. In certainembodiments, the upper surface 24 has a radius of curvature ρ₁ (see FIG.5A) that is less than that of a conventional golf ball (a conventionalgolf ball has a radius of curvature of about 0.84 inch); typically, theradius of curvature ρ₁ of the upper surface 24 is less than 0.6 inch,and can be between 0.3 and 0.5 inch. Having a radius of curvature ρ₁that is less than the diameter of a golf ball can result in the golfball resting above the upper surface 24 when on the tee 10, therebyreducing the contact area (and, in some embodiments, friction andsurface irregularities) between the golf ball and the tee.

Referring now to FIGS. 1, 2, 3 and 5A, the prongs 26 a, 26 b, 26 c, 26 dproject upwardly from the periphery of the base portion 22. In theillustrated embodiment, each of the prongs 26 a, 26 b, 26 c, 26 d isidentical to the other prongs. As such, only one prong 26 a will bedescribed in detail herein; those skilled in this art will appreciatethat the discussion is applicable to the remaining prongs 26 b, 26 c, 26d also.

The prong 26 a is arcuate when viewed from above (FIGS. 2 and 3). Insome embodiments, the prong 26 a has a secant length β that is greaterthan the diameter of the largest dimple of a conventional golf ball(i.e., about 0.160 inch). Typically, the secant length of the prong 26 ais between about 0.170 and 0.200 inch. With a prong that has a secantlength that is greater than the diameter of a golf ball dimple D (seeFIG. 3), the interaction between the prong and the golf ball should belimited to the outer skin of the golf ball (i.e., that portion of theouter surface of the golf between the dimples), which can reduce thefriction between the tee 10 and the golf ball.

Referring now to FIG. 5A, the prong 26 a also has a convex contactsurface 28 upon which a golf ball rests. This contact surface 28typically has a radius of curvature ρ₂ that is between about 0.040 and0.060 inch. The inclusion of the convex contact surface 28 on the prong26 a can reduce the amount of contact area between the tee and a golfball resting thereon, which in turn can reduce the friction between theball and the tee 10 and the influence of surface imperfections in thetee on ball flight.

As can be seen in FIG. 2, the prongs 26 a, 26 b, 26 c, 26 d areseparated from each other by notches 30. As such, they define adiscontinuous annulus A about the periphery of the support cup 20 thatcan support a golf ball. This discontinuous annulus A typically has adiameter of between about 0.4 and 0.6 inch. In the illustratedembodiment, the prongs 26 a, 26 b, 26 c, 26 d are positioneddiametrically opposite from one another across the base portion 22;however, in other embodiments prongs may be arranged about the peripheryof the support cup 22 differently. Also, although four prongs 26 a, 26b, 26 c, 26 d are included in the illustrated embodiment, otherembodiments in which at least three prongs are included are alsocontemplated (e.g., a tee of the present invention may have three, fiveor six prongs).

As can be seen in FIG. 2A, a golf ball G resting on the tee 10 contactsthe tee 10 only along four contact arcs C (one arc for each prong), withthe result that the ball has very little contact area in its interactionwith the tee 10. As a result, a golf ball struck from a resting positionatop the tee 10 may experience less friction and, thus, may travelfarther than a golf ball struck with a conventional tee. Further, thereduced contact area can diminish the possibility of surfaceimperfections in the tee 10 influencing ball flight. In someembodiments, the contact area may be less than 0.0045 in², and even aslow as 0.0036 in².

Other aspects of the tee 10 may also improve performance. For example,the presence of the flutes 16 a, 16 b may assist in preventing twistingof the tee 10 on off-center shots. An off-center shot can tend to “spin”a tee into the ground; this twisting motion can adversely impact thelaunch of the golf ball at impact. The presence of the flutes 16 a, 16 bcan prevent such twisting and thereby provide a more stable launchplatform.

Also, the tapering of the main body 14 can improve the life of the tee10. As described above, a tee can experience significant force whenstruck with a golf club and tends to fracture at its interface with theground. The tapered shape of the main body 14 creates a tapered hole inthe ground upon insertion. As a result, at impact the tee 10 can easilyexit the tapered hole rather than simply snapping, enabling the tee 10to be re-used.

The tee 10 may be made of any number of materials known to those skilledin this art to be suitable for tees. Exemplary materials includepolymers such as polylactic acid (PLA), PHA, and, in some instances,wood. In some embodiments, the tee 10 may be formed of a biodegradablematerial such as those described in U.S. Pat. No. 5,844,066 to Kakizawa,U.S. Pat. No. 5,914,381 to Terado et al., and U.S. Pat. No. 6,213,970 toAnderson et al., the disclosures of each of which are herebyincorporated herein in their entireties. In certain embodiments, it maybe desirable to employ a biodegradable polymer, such as a polylacticacid-based material, and in some embodiments it may even be desirable toemploy a biocompostable material. An exemplary material is a polylacticacid-based material with flax fiber or other impact modifier. It may bedesirable to select a material that has a low coefficient of friction,as doing so may decrease the amount of ball-tee friction.

The tee 10 may be formed by any technique known to those skilled in thisart to be suitable for the production of items formed of the material ofchoice. For example, if a polymeric material is used, injection orcompression molding or machining may be a suitable manufacturingtechnique.

The foregoing is illustrative of the present invention and is not to beconstrued as limiting thereof. Although exemplary embodiments of thisinvention have been described, those skilled in the art will readilyappreciate that many modifications are possible in the exemplaryembodiments without materially departing from the novel teachings andadvantages of this invention. As such, all such modifications areintended to be included within the scope of this invention. The scope ofthe invention is to be defined by the following claims.

That which is claimed is:
 1. A golf tee, comprising: an elongate shafthaving opposed upper and lower ends, the lower end configured to beinserted into an underlying surface; and a support cup that isconfigured to support a golf ball from beneath, the support cup mergingwith the shaft, the support cup having an arcuate base portion with aradius of curvature of between about 0.3 and 0.5 inches, and furtherincluding at least three arcuate support prongs projecting upwardly fromthe base portion, each of the support prongs having a convex contactsurface and being of a secant length that is greater than that of adimple of a golf ball, such that the total contact area between thecontact surfaces and a golf ball resting on the contact surfaces isbetween about 0.0036 in² and 0.0045 in².
 2. The golf tee defined inclaim 1, formed of a biodegradable polymeric material.